TYMOSHCHUK, O. 2023. STUDY OF THE ACCURACY OF IMPROVED METHODS OF CALCULATING THE TIGHTNESS PARAMETERS OF OIL-FREE PISTON SEALS. Herald of Khmelnytskyi National University. Technical sciences. 329, 6 (Dec. 2023), 373–379. DOI:https://doi.org/10.31891/2307-5732-2023-329-6-373-379.